Developing transmission by optical conductors, in particular in local networks that have many stations and changing configurations, leads to researching ways of enabling couplers to be connected along an optical conductor without having to break or alter the optical conductor.
Connecting station equipment to an optical conductor often requires relatively difficult operations to be performed on site, particularly for optical conductors used in industrial networks, and these operations can give rise to non-negligible losses, e.g. of about one decibel per equipment connection.
A known way of solving this problem makes use of passive optical T-type couplers made either using "fiber" technology, or using "planar guided optics" technology. This adds an insertion loss of one decibel per coupler to the loss of one decibel due to each connection, and consequently reduces the number of items of equipment that can be served by one common optical conductor.
Another way of solving the problem consists in using regenerative couplers. However, the number of items of equipment that can be served by the same conductor is also limited because of the increase in the propagation times due to the delays caused by regenerative processing at the couplers and to the build up of jitter in the transmitted signal.